The Watchman
by Nimbus Llewelyn
Summary: YAHF. Xander wore a special costume no one could identify that night. No one knew what he did, and he claimed he didn't remember. But when he got angry, his eyes glowed... gold. I own nothing save my plot ideas.
1. Chapter 1

That fateful Halloween, many things happened. Willow discovered what it was like to be a ghost, Buffy discovered that Angel liked her best as she was and all of them discovered that Giles had once been very scary. As for Xander… what he discovered, no one knew, because he claimed he didn't remember a thing.

There was something about the all too innocent tone of his voice and the slightly drawn look to his face that suggested he was lying, but everyone was too relieved that he was all right to press the point. The only indication of anything different was that he seemed to have toughened up slightly, barely noticeably, and fought with rather more grace and skill. That and the fact that his eyes went gold briefly whenever he got seriously angry.

And there was an air about him, which Buffy, Giles, Angel, Oz after his transformation and Willow, as her powers developed, began to feel. A vibe of something incredibly dangerous, a wild power barely in check. If Xander's parents had been talkative, they would have mentioned how often he woke up screaming.

Even Spike avoided antagonising him thereafter, preferring to keep half an eye on him at all times, and Angelus eyed him like he was a time bomb that the Master Vampire would enjoy setting off. Preferably from a distance of several thousand miles away.

Drusilla was fascinated with him, babbling about 'the one who sees is become the golden watchman, but Miss Edith knows he doesn't want to release the dark one'. Xander had given her a look with more than a little golden power in it, and she'd backed down, uncharacteristically silent.

When he'd found out that Joyce had kicked Buffy out of the house, Joyce swore that his eyes had burned a furious golden colour, and that he had gripped the sideboard so hard that his knuckles were completely white. He had said, "How could you?" Then turned and left, slamming the door hard. Later, Joyce noticed several finger shaped dents in the sideboard.

Faith had been drawn to him like a moth to a flame, and when she'd gone bad and tried to rape and kill him, Angel had come in, ready to play the hero, only to find a Faith shaped hole in the wall and a scared looking Xander hugging his knees on the bed.

At the time they had put it down to trauma, but the fact that Faith stayed a very long way away from him after that suggested something else was at work. But if there was, Xander was decidedly cagey about it, and no one felt like pushing someone who looked disturbingly like a wolf at bay. Giles theorised that Halloween had released and integrated the remnants of the Primal Hyena spirit into Xander, which would explain the bursts of strength and the occasionally gold eyes, and his desire not to talk much about it.

When the Mayor had ascended, he declared that something smelled strange, and powerful , about Xander. It might have been the Scoobies collective imagination, but they thought he'd look a little frightened.

Later, Buffy reported incredible power, even more than she had expected, flowing through her when she fought Adam. Certainly, she hadn't expected to be able to throw Adam across the room to make a large dent in the opposite wall with one relatively light punch. She hadn't noticed Xander's sad smile, nor put much on his look of utter torment and terror after the First Slayer decided that she was declaring open season on their dreams.

When Glory came to town, Xander became introspective, and was occasionally heard arguing with himself. About what no one knew. Finally, when Glory took Dawn, Xander walked into the Magic Box and handed Giles a couple of comics and a yellow costume with a blue cape.

"That's what I wore on Halloween. It's who I am."

He said nothing more, just turned and left, kissing Anya briefly, then arranging his face into a grim expression, he went to get ready for the showdown.

Giles read the comics, re read them, then, most uncharacteristically, began to cry. He wouldn't tell Anya what it was, but he grieved for the boy whose little remaining innocence had been stolen by a chaos mage who had shoved the memories of tortured and insane man with earth shattering power into his head. Just for a good laugh. He vowed to make Ethan feel pain. Lots of it.

As Buffy outlined their plan of battle, no one interrupted until she mentioned the part where she would be dealing with Glory. Anya provided the Dagon sphere and pointed out the uses of the Troll hammer. Then Xander spoke.

"I'll deal with Glory. You get Dawn."

"Xander, are you out of your mind?! She'll kill you in, like, ten seconds, even with Willow's reverse brain suckage!" Buffy said incredulously. Everyone else, Giles aside, looked at him as if he had gone mad.

Xander just looked at her levelly, then flicked his gaze to Giles who cleared his throat and said, "Buffy. He's right. Xander's tapped into a strength that would give even Glory pause." He paused, made sure he had everyone's attention, and said, "Even if she was ruler of her Hell Dimension once more."

Buffy's jaw dropped, then she thought for a moment, and shut her mouth. "This is about the gold eyes isn't it," she said quietly. It was not a question, just a statement. Giles nodded.

"On Halloween, Xander became a superhero. One called 'The Sentry'," Giles said, looking to Xander to confirm.

Xander nodded and added, "Think Superman on steroids. And more mental problems than the Joker."

Buffy blinked. Well, that answered her question about why he hadn't used it before. He was scared. Scared of his own power. Suddenly, the state he had been in when Angel found him before Graduation made sense. He hadn't been scared _of_ Faith, he had been scared about what he might have done _to_ Faith. She looked around the room and saw everyone else reach the same conclusions she had.

In a low voice, Xander began to explain the dual nature of the Sentry and the Void. The god complex of Robert Reynolds, and the role of the Sentry in the Fall of Asgard. The casualty figures of the Void's attacks. The desperate measures taken to try and keep it in check. The cataclysmic effect of the failure of those measures.

"I'm scared of this power guys, I'm terrified. I don't know what it'll turn me into. That Halloween, I flew into the heart of the Sun itself to try and get away from my fear." He looked around at them softly, not including Spike, and said, "It was the thought of you guys that brought me back." Then his voice hardened. "I'm going to kill Glory. Not beat her. Kill her, and throw her body into the Sun. Then I'm going. I'm going to see the Universe. To find out who I am and what I've become. Maybe I can get this power under control, use it for what's right. Maybe."

He turned to look at a dismayed looking Anya, and said quietly, "I'm sorry, I'm so sorry. But no matter how much I love you, I can't risk the Void on Earth, especially where there's no one else able to contain it. I love you, and I swear that I will do my best to come back someday."

Anya just nodded, tears in her eyes, and he kissed her gently. No one said anything, and even Spike didn't make a snarky comment. Of course, that was partially to do with the fact that Xander could vaporise him with a thought. But only partially.

That night, faces were grim as they followed Tara to the ramshackle tower, built by the mad for a madder God.

Willow drained Glory's sanity into Tara, then Xander stepped forward. Glory frowned.

"Who are you? I was expecting the Slayer." Then she shrugged, and said as she ran forward, not a blur but still very fast, "I need a snack anyway."

She was deeply surprised when a strong hand caught her by the throat and lifted her into the air as if she weighed no more than a piece of paper. She looked down into a pair of glowing gold eyes and got the sudden sensation that she had bitten off far more than she could chew.

"Glorificus. You don't know what it is to be a god. You take the easy path, and just take, take, take from everyone around you, using and abusing your power," Xander said coldly, then pulled her close and hissed, "I know what it's like to give in to evil. I know how good it feels, just… letting go. But I have a conscience. Friends. These are the fetters that bind me, and the bulwarks that support me. And I'm going to kill you for hurting them."

Glory managed to escape the crushing grasp, punched him hard, sending him flying backwards, and said mockingly, "So you know what it is to be a god, insect? I don't think so. You're strong, I'll give you that but nothing compared to m-"

She was cut off as Xander blurred to within punching range and hit her with a blow that would have crushed several trucks. As it was, she went sailing away, and Xander took to the skies after her.

As Glory struggled out of the rubble of what had once been a convenience store, she knew that she was facing something that was both much stronger than she was. And it was very angry. This was borne out by the figure that was now glowing, glaring and hovering all at once.

"Where did you learn that trick, insect?"

"Chaos Mage. He decided it would be funny to turn me into a man with the power of a million exploding suns for a night. It stuck," Xander said curtly, before lifting her up and throwing her like a dart several thousand feet in the air. As she fell, she was not scared of the fall itself, but unnerved by the ease with which her opponent had thrown her. Then she screamed. Because Xander Harris, the new Sentry, was diving at her from above with murderous intent. The impact left a crater half a mile wide in the Sunnydale desert.

Glory wheezed and twitched. The impact had nearly driven her back to her mortal form. She was bruised, battered, broken and bleeding and on the edge of defeat, but her opponent didn't even look particularly ruffled.

She gasped as he lifted her up with one hand, eyes no longer glowing, and looking weary, but cold. Not in the physical sense, as she sensed he could have fought her all night with one hand, but in the mental sense. He said nothing as he flew her into space. He said nothing as he looked into her eyes then hurled her into the sun. She would have screamed, but no sound travels in a vacuum. And as she burned, looking into those cold eyes, made for laughter but with no humour left in them, she realised that messing with the Slayer and her family would be something that no demon was likely to do anytime soon. As her physical form was obliterated, those eyes never left her, watching as she died.

Xander flew back to earth, for long enough to say that he was alive and Glory was gone. Then, kissing Anya once more, he set out for the depths of space.

The Trio were plotting. As they did so, writing ideas on the whiteboard of evil, the door to their basement exploded. Out of the dust strode a very angry looking Xander Harris, eyes aglow. Jonathan summarised the situation concisely.

"We're fucked."

"I think I just wet myself," Andrew said nervously, and Warren shuffled away from him.

"You know, when I come back from exploring the universe, right at the top of the list of things I don't want to hear is that some Big Bad wannabes have been messing with Buffy," Xander said conversationally, tone belying his expression which was just this side of homicidal.

"Exploring the universe?" Warren asked, scenting an opportunity. "Well, we, that is the Trio, can help you with dealing with your knowledge. We're _really _good listeners."

Xander chuckled darkly. "The things I could tell you would melt your brain. I fought in the last Great Time War, side by side with Time Lord Generals. I destroyed half the enemy Fleet before they used an emergency temporal shift to escape. I looked into the Eye of Harmony, I flew through it to another universe and I saw things you couldn't comprehend. And that's all I'm saying."

"Ok, let's say we believe what you're saying," Warren said carefully, recognising that no matter how insane or delusional this man might be, he had just blasted through their steel door like it wasn't there. And there was something in his voice that suggested he might be telling the truth. "Who are you?"

"Name's Xander Harris. A name you're more likely to recognise is one I gained after a run in with a chaos sorcerer one Halloween," Xander was slightly pleased to note that Jonathan had just gone extremely pale, and Xander said, "Would you like to say, Jonathan? You look like you know."

And indeed Jonathan did. Despite his naivety in working with the Trio, Jonathan was a smart boy, and tended to think faster when his life was in danger, and with the help of his vast comic knowledge, he'd been connecting a lot of dots.

Fact, four years ago, a powerful Chaos mage had transformed everyone into their costumes. Fact, the effects had occasionally lingered, as Jonathan going as a Jedi had clued him into his magic. Fact, Xander had been at least as geeky as him, at least once upon a time, so would have gone as some comic book character. Fact, Jonathan was pretty certain only a few comics characters could survive something like flying to another universe and whatever a Time War was, and even fewer of them had eyes that glowed with yellow light every now and then, and even fewer could, according to rumour kill a HellGod in hand to hand combat. Or _throw her into the sun_.

"Guys… Xander's the Sentry," Jonathan said. Andrew looked like he was on the verge of a heart attack or a nerdgasm, and Warren just looked outright terrified at Xander's suddenly shark like smile, which was really unnerving since Jonathan had known him since just after Kindergarten.

"It's so nice to be recognised," Xander said, grinning a grin with far too many teeth in it. "Now. Whose head should I tear off first?"

"Please, have mercy on us!" Andrew wailed, and Warren pushed Jonathan forward, bowing and saying, "accept this sign of our penitence o mighty one."

"Jonathan's the only one worth spit among you lot, so I'll spare him. Andrew's weak and just follows the leader meaning he's not worth killing…" Xander said, then his eyes lit upon Warren, ignoring Andrew's indignant protests, "that leaves Warren. Murderer, attempted murderer, thief, and probably a rapist or an attempted rapist if you aren't building robots any more. Tell me, why should I spare you?"

"Because I can be better, because I can make a better life if you let me live, _please_!" Warren begged, inwardly thinking that he needed those orbs as soon as possible.

Xander examined him for a moment, then grabbed Jonathan and flew out.

When he arrived back at the Casa del Summers, he noticed something was wrong. Spike's coat was on the banister and there was a bruise on Buffy's leg. And she was still weak from the patrol she had come in from when he got back, and she'd told Xander about her sleeping with Spike. He'd accepted it, mostly because Anya was attempting to drag him away for reunion sex, and along with Willow descending into Magical drug abuse, Dawn's kleptomania, the rise of the Trio and the other problems that had beset the Scoobies since he'd left, and the reunions, tearful and otherwise, he was a bit deluged.

"Xander?" Buffy said, seeing his hair bleached literally white with fury.

"_Where?"_ he hissed.

"What's Jonathan doing here?"

"Information," Xander said curtly, dropping the terrified petty wizard on the couch. "Now where is that no good rapist vampire?"

Buffy shrugged helplessly, not bothering to ask how Xander knew, and said, "He just ran away all of a sudden."

Xander disappeared. A few moments later, a crypt sitting Clem got the fright of his life when the door of the crypt exploded and a glowing Xander floated in.

"Spike. Where?"

Clem, realising he was not the object of Xander's wrath (and feeling a little sorry for Spike), said, "He left for a while. Said he wanted to make things change," as the sentence finished, Xander was gone.

Spike was gunning his motorbike, when he looked down at Sunnydale and saw a rising yellow light. If a vampire's blood could get any colder, his would have frozen. Goldenboy was back in town, and it looked like he had heard of Spike's… misdemeanour. Spike turned off the bike and got off. There was no point in trying to outrun someone who could fly faster than light if he so wished. Especially if said person wanted to obliterate him. The light was closing fast and was beside him less than ten seconds after he'd dismounted.

"Explain in five words or less why I shouldn't destroy you," Xander said curtly.

Spike paused, then said. "Getting. My. Soul. Back. Wanker."

A lot of the anger and power left Xander and he looked closely at Spike. Then he said, "How?"

"Ever heard of the Demon Trials?"

Xander shook his head, now honestly curious.

"They're a series of challenges, of tests that if a demon passes them, they can get a prize, a wish that would normally be impossible," Spike said.

"Then why isn't the world ruled by demons and there are still Slayers?" Xander said, eyes glinting dangerously.

"No demon's ever survived them, not in 10,000 years." He shrugged. "If I succeed, I… well, end up hopefully not too much like the poof. If I fail, you don't have to bother killing me."

Spike then yelped as a sharp telepathic probe sifted through his thoughts, then abruptly retreated. Xander nodded to him, stepping to the side of the road and said harshly, "If I ever see you in Sunnydale or near Buffy without a soul again, I'll end you."

Spike nodded jerkily and got on his motorbike, starting the engine and racing away. Xander watched for a moment, then disappeared. He flew north and west, crossing the Atlantic in moments, then shifting planes as he hit the Cardiff Rift. One thing he had discovered in the Time War was that Rifts in time were an easy form of transportation, particularly between worlds. And he was looking for a very particular world.

"BOB! DON'T LET THEM WIN!" Norman Osborn screamed, and everyone looked on in horror as the Sentry flew towards Asgard with the intention of destroying it. Before he could hit it, however, a white blur hit him hard and knocked him out of the sky. The second blur was hovering, apparently watching the no doubt surprised Sentry. Only Thor had ever been able to smack him around like that, and now even the Mighty Thor was having trouble. Everyone was gobsmacked. Even Osborn had shut up.

"Odin's eye," Thor breathed, feeling the dimensional disturbance. Then, incredibly, he smiled and said to himself, "It seems we have some assistance this day."

Xander dropped down towards the Sentry. He was wearing a similar suit to the Golden Guardian of Good, but he had altered it. Now it was white, with a golden cape and a golden W in place of an S. Thor followed him and nodded his thanks to the dark haired mortal, who nodded back.

"Thor Odinson. That isn't the Sentry," Xander said. "It's the Void, in full control."

Thor sighed. "I suspected it was so. Robert was always a little weak willed. And who are you, traveller?"

"I go by the Watchman, Thor," Xander said, then flashed a smile, and said, "but you can call me Xander."

By this time, the Void was watching them silently, doing nothing. Then it said, "So. One from beyond interferes. Well, we can't be having that." As it said that, it blasted Xander. Or tried to, as he negligently blocked and dispersed the blast. In response, the Void blurred, attacking Xander head on, and the two incredibly powerful beings began to brawl. Thor watched and waited for an opportunity to smite the Void, but it did not come.

Meanwhile, in Washington, the President was puzzled.

"So, the Sentry, who you say has power that's off the charts is being taken down by someone we don't even know about?"

"That's the basic idea, sir, but I wouldn't rule out the Sentry, or whatever he's become just yet." As he said that, the unidentified meddler was punched several miles away. This didn't seem to faze him all that much, and he just got up and took the fight back to the abomination that had once been the Golden Guardian of Good, landing a blow that smashed the Sentry into the water table.

"And what do we do now?"

"I think we should wait, sir. This new person and Thor seem to have the situation in hand."

Indeed, as the general said that, Thor whopped the grounded Void with an enormous thunderbolt in conjunction with a similarly sized blast of golden energy from the newcomer.

"So the plan is just to wait and see?"

"Mr President, we know for a fact that Thor or the Sentry could tear the planet in half if they so wished, and I have no doubt that this newcomer would have no problem doing the same. Not only that, but the Avengers are there. What could we possibly do that could make a difference?"


	2. Chapter 2: Out of Balance

Xander groaned. The Sentry/Void/whatever really packed a punch. He backflipped to get away from an energy blast, and took off. He wanted something really _big _to hit the Void with. Not far away he found something. He grinned and uprooted it.

And that was how the Avengers witnessed the Void getting cold cocked by a bronze cast of Ronald McDonald.

"Well," Spiderman said as Xander began playing whack-a-mole with the Void. "I never thought I'd say this but, go McDonalds!"

"That one has a strong sense of chaos about him," Loki commented. "Almost as if it empowered him." He grinned as Xander knocked the Void down again. He then began to wind up for a massive swing. "I like his style," he added.

"I have to agree with you," Spiderman agreed. "He's a bit like me."

"God, I hope not," Fury said. "One of you is more than enough."

Spiderman nodded emphatically. "Clones are no fun."

"Unless they happen to be female," Loki said with a lecherous smirk.

"Do I want to know?" Spiderman asked.

"If you can't work it out, I'm not going to be the one to tell you," Loki replied smoothly, earning a bark of laughter from Fury. "My brother would be on my case about corrupting young minds."

He cocked his head and narrowed his eyes as he stared at Spiderman. "There is an enchantment on you that was not there when last we met. It is the centre of a powerful reality shift. Why did you not call me?"

"You have Loki on speed dial?" Fury asked suspiciously. "Why?"

Loki glowered at him. "He helped me save my daughter's life, Fury. Loki does not forget his debts," he said curtly. He looked back at Spiderman, as Fury examined Loki. "Back to my original question. Why did you not call me?"

"I'm under a spell?" Spiderman asked, puzzled.

"Ah, a memory enchantment," Loki said, eyes narrowed as he looked at something only he could see. "How is the lovely Mary Jane, by the way?"

"Fine," Spiderman said with a shrug.

"You aren't married to her?" Loki asked in bemusement.

Everyone stared at him like he'd grown a second head.

"I see," he said quietly. "Are you courting anyone?"

"Yeah, Carlie Cooper," Spiderman replied.

"Then why do my diagnostic spells say that you have been intimate with a magical construct recently?" Loki asked.

Spiderman just stared at him. "What?"

Loki sighed. "Who were you last intimate with, Spiderman?"

"Carlie. Why?"

"She's a magical construct. The enchantment on you is Mephisto's work, as, I suspect is the construct. Whatever he did separated you from your young lady, and as a cruel joke, he sent a construct to fall in love with you," Loki said, voice slightly distant and eyes slightly glazed as he made a few hand gestures. "A love enchantment and a forced empathy spell, to make the construct's job easier. My, this is complex, and much more effort than he usually puts in for any save my brother or that Silver Surfer person. I would ask what you did to annoy him, but you seem to annoy everyone."

"Hey," Spiderman complained, reeling slightly.

"The love enchantment and the empathy enchantments are gone," Loki said, as Spiderman sagged.

"How did I ever fall in love with that woman?" he moaned.

"If you'd been listening, you would know," Loki replied, then his face darkened. "This is _foul_," he hissed. "You were psychically influenced into doing something you normally would not."

The Avengers shared sidelong glances as Thor and Xander began to play tennis with the Void. What was so foul that it disgusted even Loki?

"What?" Spiderman asked, with some trepidation.

"It is best you remember it for yourself," Loki said, some sympathy in his voice.

Spiderman fell to his knees and screamed.

"What did you do to him?" Fury demanded.

"Nothing. I just let him remember," Loki said. "Yon Spiderman is a reasonably pure and very heroic soul, much like my brother. Mephisto likes to take or corrupt such souls, and with the help of circumstance and some mind alteration, he did. Spiderman's aunt was shot by an assassin and was dying. Mephisto offered to heal her, but at a price."

"My marriage," Spiderman said, broken. "And my unborn daughter."

"Fear not, Spiderman," Loki said. "What can be done can also be undone." He smiled slightly. "Mephisto is a little distracted, playing landlord to my daughter, Hela. I cannot reverse it entirely, but I can restore your marriage. And…" he added, eyes closed, then smiled. "One father to another, I can restore your daughter."

He snapped his fingers and Mary Jane appeared, looking a little surprised. Her hand went to her stomach, and then she looked at Loki, who casually handed her a pregnancy test, then snapped his fingers again.

"She'll be back in a minute," he said calmly.

"Do you have to snap your fingers every time you teleport someone?" Fury asked.

"No. I just feel like it right now," Loki said casually. A couple of minutes later, he teleported Mary Jane back.

"I'm pregnant," she whispered. "How?"

Loki flicked her forehead, and she blinked. "That's how," he said, then looked over at the sobbing Spiderman.

"Mrs Watson-Parker, I think your husband needs you right now," Loki said, and Mary Jane nodded dumbly. "The construct has dissipated," he added.

"Why are you doing this?" Captain America asked quietly.

"Because I owed him a debt, Captain. And I too have been a father and a husband, a bereaved one of both, at that," Loki replied as he watched Mary Jane and Spiderman hug. "It costs me nothing. And it will piss off Mephisto." He smirked. "Besides, imagine how much chaos a daughter of those two will cause. I lose nothing, and discharge a debt at the same time."

The Void went sailing over head as Xander yelled, "HOME RUN!"

Unfortunately, as it went sailing overhead, one of its tendrils reached out for Spiderman and Mary Jane. The Avengers moved to intercept, but one figure beat them all to it.

"NO FOUL CREATURE, I WILL NOT LET YOU DO THIS!" Loki said, leaping in front of the tendril. "I SAY THEE NAY!" he cried as he protected the couple with his body. The tendril tore him away. A few moments later, despite the power of the Norn Stones, Loki was torn into chunks. Just before he died, he managed to say, "I am sorry, brother."

The Void then turned on the Avengers. And was hit by both a literal and metaphorical thunderbolt, of equally epic proportions.

"YOU HAVE STRUCK AT THE HOUSE OF ODIN, FOUL CREATURE!" Thor bellowed, tears streaming from eyes that were white with fury.

Xander's eyes were glowing gold. "You killed a man who could have done so much good. You tried to kill a young couple in love," he said dangerously, then began to pummel the Void, blows moving faster than sound. "No more kid gloves." His next punch sent the Void to the edge of the atmosphere.

"He's all yours, Thor," Xander said quietly. "For what it's worth… I'm sorry."

"Aye, friend Xander," Thor said, grief and fury in his voice. The Void fell. It was hit by an enormous lightning bolt, the likes of which the world had never seen before. The Void landed in a mile wide crater. Xander flew above the crater, and released a blindingly bright blast of energy. The crater was about ten miles wider, and all that was left was a smoking skeleton. Xander collapsed, panting and looking like he'd just ran three marathons.

Thor looked at him, and said, "Asgard thanks you, Friend Xander." He wrapped the Sentry's body in his cloak and flew away.

"As does Earth," Fury said. "Come on. Let's clear up and debrief."

Xander stood on wobbly feet.

"Not you, son," Fury said. "You've done more than enough."

Xander nodded, and sat back down next to Spiderman and Mary Jane. He looked at them, then just at Mary Jane.

"Loki undid Mephisto's reality warp?" he asked tiredly.

The two nodded mutely.

"Take my advice. Just kiss, screw whatever. Stay close to one another, physically and spiritually. It'll help you adjust," Xander said, before apparently going to sleep on the ground, head settling with a thump.

"And I thought my life couldn't get any weirder," Spiderman said after a long moment.

"Me too, tiger," Mary Jane said quietly.

"I can't believe I -" Spiderman began, before Xander interrupted, opening one eye.

"If you dare start brooding and blaming yourself for what you did under magical influence," Xander began.

"I'll make you sleep on the couch," Mary Jane said, and Xander chuckled as Spiderman clammed up.

"I was just going to punch him till he wised up," Xander said, smirking. "Your threat is scarier."

"I'm his wife," Mary Jane said with a modest shrug.

Xander chuckled as he dropped off.

"So traveller Xander, where have you come from?" Thor asked.

"And where did you get your powers?" Tony added.

"Who are you?" Steve asked.

"I come from a parallel world, one where demons walk the earth and extra-terrestrial races are soon going to make their presence known. You lot are a comic book series over there. As for my powers, it all started one Halloween several years ago. A Chaos Mage, a worshipper of Janus, enchanted all the costumes he sold so that the wearer would turn into their costume. I dressed up as the Sentry, and the spell caught his memories just after this." Xander said, looking around.

"But in those memories, the Void destroyed Asgard, killed Loki who switched sides to help you, and was eventually destroyed by first the Helicarrier landing on his head and forcing him back to Robert Reynolds, then Thor providing a mercy kill when he started reverting to the Void, finally throwing his body into the sun. So as you can imagine, when he found himself in my body, he flew into the sun, hoping to die. But after the spell was broken, I retained his powers… and his memories," Xander said, grimacing. Tony winced. Anyone with Robert's memories who managed to stay sane was truly remarkable.

"So I flew back down, and kept my powers quiet, because unlike here, there was literally nothing that could stop me if it turned out that I had my own version of the Void. Or even if I went bad of my own accord. So I restricted myself to Captain America levels or below of strength, except in direst need, and most vampires avoided me. They knew what I was, even if no one else did. Then, three years later, the Dimensional Key – ask Doctor Strange about it – was bound in human form and sent to the Slayer – mystical warrior, she who fights vampires and demons yadda-yadda – to hide it from an earthbound Hellgoddess called Glory who would have used it to get home and send the world into hell. The human she was hidden as was my best friend's sister, Dawn Summers, and our memories were all altered to fit. Eventually Dawn got kidnapped, and Buffy Summers, the Slayer, wasn't strong enough to beat even a weakened Hellgoddess like Glory. So I revealed myself. I beat her down and hurled her into the sun. Then I went to explore the universe, and get control of my power," Xander rubbed his face as if tired, and sighed.

"If you wish to stop Xander, we can hear the rest of the tale another time," Thor said. "We are in your debt for the assistance you have given us today." The rest of the Avengers nodded in agreement.

"Thanks, but I'd rather get this over with, if that's all right. Anyway, that was when I got pulled into the Last Great Time War. It's too complex to explain, but it amounted to aloof Time Lords, the first Time Travellers and guardians of the Laws of Time, versus Daleks, insane omnicidal extra-terrestrial Nazi's in what amounts to a super strong mini tank. They make the Red Skull look sane and reasonable." Steve and Bucky both winced. Xander shot them a sour smile briefly before continuing.

"I could never miss out on fighting the good fight, and the Daleks were as evil as they came and the entire universe was at stake, including my Earth. So I joined up with the Time Lord's. I fought at the Fall of Arcadia, I destroyed the Nightmare Child, and I fought at the First Battle of Gallifrey, home planet of the Time Lords around five thousand times. That's an occupational hazard in a war where both sides have advanced time travel technology." Tony and Hank looked very interested at the mention of time travel.

"It was then that I discovered where my, and by extension, Robert's powers came from. The serum he drank moved his molecules an instant into the future. According to the Time Lord scientists, this meant he, and me, was tapping into a portion of the power of the time vortex itself, hence the gold colour and matter manipulation. Somehow he was able to sustain it, because normally the sheer power kills its host after a short while, but it drove him insane instead. And it let something else in," Xander said, tone forbidding.

All the Avengers leaned in.

"I call it… the Nightmare Child," Xander said quietly. "You call it the Void. It is one of the few things I genuinely fear. Not for myself, but for what it has shown itself to be capable of, all across the Multiverse. I killed a manifestation of it in my home universe, one that had feasted on countless lives, on the carnage of a multi-dimensional war, in battle. I would rather not have to repeat the experience."

"As for who I am? I'm Alexander Lavelle Harris, one of the Scooby Gang, the White Knight, friend of the Slayer, slayer of Vampires and Twinkies, and I am now the Watchman." The last part he said with a grin.

There was a stunned silence, then Tony said thoughtfully, "Could one of these Time Lord scientists cut Robert off from his power? Or restrict it? Because he's going to come back someday, he always does."

"Probably. But I'm not even sure if the Time Lords exist here. Besides, the war drove the Time Lords to depths they would never normally have considered, when even my admittedly immense powers proved not to be enough. Species were being rendered extinct before they evolved, time itself resurrecting people time and time again to fight in a war of endless carnage. They resurrected Rassilon, one of the founders of their society, and he formulated a plan for them to ascend to a higher plane, but at the cost of the rest of universe," Xander said. "The Final Sanction, they called it."

"One of their generals, my friend the Doctor, found out what he was doing, and took an ancient superweapon known as the De-Mat Gun that wiped its target from time and rewired it into the Moment. Gallifrey burned. Everything burned. Ten million Dalek ships and countless Time Lords, men, women, children alike, all burned. The Moment ended the war, saving the universe at the cost of his family, his home and everything he had ever known. I haven't seen him since I fled the destruction of Gallifrey, which is quite worrying since I managed to save…" Xander looked thoughtful for a moment as if searching for the right words.

"… the _minds_ of a whole bunch of young Time Lords, including his granddaughter. But that's another story."

Xander yawned. "Now, I need some food and sleep, if that's okay."

"Of course," Thor said, helping Xander up. "Stark, can you organise transport?"

"'Course," Tony replied, flying off.

Having hung out with the Avengers for two weeks, Xander flew back through the rift and crossed the Atlantic at a leisurely Mach 1.5, flying into the clouds as he flew overland. Just in case. When he landed outside Revello Drive and dismissed his costume, he could tell something was wrong. The door had been torn off its hinges, the ground floor was mostly destroyed. Jonathan was beaten and bloodied, barely breathing, but he seemed fine.

Spike had been nailed to the wall with kitchen knives driven to the hilt. Thankfully, he was unconscious. By the looks of things, someone had already tried to remove the blades, but they were stuck fast. Xander removed the knives by tearing out the relevant section of wall and working from there. Quickly he realised that there was no one else on the ground floor. He flew up the mostly destroyed stair case and heard weeping, following it to its source. Dawn was hunched on the ground in an utterly destroyed room, with two of the walls just missing, next to a prone Tara.

"Dawnie? Are you ok? Where are Buffy, Willow and Giles?" Xander asked gently.

"Xander," she yelled, throwing herself into his arms and hugging him tightly.

"It's ok Dawnie, I'm here," he said, hugging her tightly and stroking her hair as she cried into his shoulder. "Are you all right? And where are the others?"

"I-I-I'm f-f-fine," she stuttered, and then, between sobs, the whole story came out. Warren had come by earlier that day, crowing about how he was invincible. He had walked in, and when he realised Buffy was out, shopping with Dawn, he had grabbed Willow. Jonathan and Spike had tried to stop him, and what Xander had seen downstairs was the result. He had taken Willow upstairs and forced himself on her.

When Tara tried to intervene, he'd smacked her away so hard that her neck had snapped. At that point Willow had lost it, and hit him with every hex she could think of, destroying the room. But it had all rolled off him, and he had laughed and completed the act, leaving her. Buffy and Dawn had got back, and Buffy had immediately taken Willow to hospital and said she was going to find and beat Warren. Giles was probably there as well, Dawn thought.

"I'm going to destroy him," Xander said coldly. "I gave him a chance he didn't deserve. Now… now I'm going to play God. I am going to give him his own personal apocalypse." He reached down and gently touched Tara. He was rewarded with a deep, raggedy indrawn breath as Tara Maclay came back to life.

"Hey Tara. I heard about what happened. I'm taking you and Dawn to Giles' house, ok?" he said kindly, as Dawn looked on in shock. Tara looked a bit lost, but nodded as he gently lifted both up and took off. A quick return trip fetched a still comatose Spike and Jonathan, and after he left them all inside, he let his anger take over. Wreathing himself in golden energy he flew up just below the clouds and he looked for Warren. There, he was fighting Buffy, and due to whatever had given him his power up, was having the better of it. Not on my watch, Xander thought. He aimed and dived.

Buffy dodged another enormously powerful but poorly aimed punch and saw a golden glow above. Her eyes widened and she backed off as the glow began to come closer.

"Aw, does the little girl not want to fight anym –" Warren taunted, before an enraged Xander collided with him at around Mach 5. The shockwave sent Buffy flying, and when her vision cleared, Xander was hammering blows into Warren, who suddenly looked a little nervous.

"I'm invulnerable! I have super strength!" Warren yelled.

"Go be invulnerable in New Jersey," Xander said, whirling him around by his ankle and hurling him northwards. Looking after him, he muttered, "Ah crap, I may have thrown him a little _too_ far…"

Then he turned to Buffy and said, "Tara's alive. She, Spike, Jonathan and Dawn are at Giles'. How's Willow?"

"Xander, Tara's dead," Buffy said, tears escaping from her eyes. "I checked. Willow's asleep for the moment. It's better that way."

"Not anymore. Thanks Buffy. Could you deal with the hopeless minion?" Xander said, pointing at a terrified looking Andrew, then taking off again and shooting after Warren. "And as I said to Dawn, 'I'm going to play God!'" he yelled as he left.

Warren didn't know exactly where he was. All he knew was it was very cold and icy, and when he turned south, he could see that there was a town in the distance. He chuckled inwardly. What were the odds? As he walked towards the town, he saw a golden blur. After that, his world was restricted to golden light, furious punches and incoherent enraged screaming.

Then it stopped, as Xander held him to eye level. Warren dazedly noted that both his eyes burned with a furious golden fire.

"So, how do you like it asshole? Being helpless as someone infinitely stronger than you does whatever they want with your body?" Xander hissed furiously.

"I don't like it, and if you let me down, I will repent and only use my powers for good," Warren said, and Xander punched him hard in the face.

He could barely see, but he could hear Xander when he said harshly, "You had your chance. You know, many people with your supernatural strength think they're invincible and accountable to no one. Many people also think that since the Sentry has many of the same powers as Superman and is a hero, he doesn't kill. Both are wrong."

Just before Xander tore his head off, Warren realised that there was invulnerable, and then, so to speak, there was invincible.

Xander looked down at the sack of meat that had once been Warren Mears. Noting a strange pouch at his hip, he picked it up and examined it. This was probably what had given him his powers. He probably should feel guilt, but he honestly didn't care. A blast of power vaporized the body, and Xander picked up the head.

"Alas poor Warren, he should have got out while he was ahead. Instead of when he was just a head," Xander said, smirking slightly, then flew back to Sunnydale. First he stopped off at Willy's. The barman looked terrified as Xander blasted the door off its hinges, getting the attention of the patrons.

"First things first, does anyone know what these do?" Xander said, holding up the orbs he had found in the pouch.

"They make the wearer super strong and invulnerable," a voice came from the back.

Xander nodded. "Thanks. The last person to wear them used them to rape one of my best friends and kill and torture a couple of others. He managed to beat up our friend, the Slayer, with that strength."

Whispers went around the room, but the demons remained attentive.

He hurled Warren's head into the middle of the room, where it landed with a wet thump.

"This is what I did to him. While he was wearing those orbs," Xander said coldly, crushing them in one hand. "I am the Watchman, and I see all. And I decree that anyone who touches the Slayer or her friends will suffer the same fate. Even if they're human. The Slayer won't kill humans because she's a better person than I am, but it honestly doesn't bother me that much. Spread the word."

Xander landed at Giles' house, and walked in. "Hey guys," he said quietly. "You ok?"

"Thanks to you, somewhat," Giles said tiredly. "Dawn tells me you brought Tara back to life."

"I did," Xander acknowledged.

"I wasn't aware that was part of the Sentry's power set," Giles said, raising an eyebrow.

Xander shrugged. "I just knew it would work. He did it once before. Besides, during the Time War, I discovered the source of my power. Time itself. And resurrection isn't hard for someone wielding Vortex energy, not if the soul doesn't actively resist."

"Have you done this before?" Giles asked.

Xander shook his head. "Robert did. Once, for me, it was nearly a resurrection. I had to heal the Lindos Organ – it's the part of a Time Lord's physiology that allows them to regenerate. It taps into the Time Vortex, and draws enough power to heal them, but messes with the cellular structure at the same time. It's why a Time Lord who draws in too much Vortex energy has to regenerate, and vent the energy."

Giles nodded slowly. "Then why have you not died from this exposure?"

Xander shrugged. "Even the Time Lords aren't sure, and they studied my powers closely, and tried to replicate my abilities to turn their entire civilisation into Super soldiers, but it didn't work."

"Well, let us be thankful that you are alive," Giles said, smiling slightly. "What happened to Warren? Buffy said you flung him northwards and claimed that you threw him to New Jersey. Then you said you were 'going to play God' and Dawn mentioned something about a personal Apocalypse."

"He's very, very dead," Xander said. "And I overshot. He ended up somewhere in Greenland."

"Did you manage to remove his power source?" Giles asked. Xander shook his head.

"I beat him till he was beyond the regenerative capabilities of the power source, then I tore his head off and vaporised his body," Xander said casually.

"You killed a human being," Giles said, without judgement.

Xander shrugged. "I'd already offered him a chance. He didn't take it. I'm a no second chances man, and he was worse than most vampires."

"What did you do with the head?" Giles asked.

"Dropped it off at Willy's, discovered his power source, crushed it and told the clientele that the same would happen to them if they even looked the wrong way at Buffy and company," Xander said. "Now, do you want me to remove Willow's memories of the… incident?"

"That's her decision. And the doctors are keeping her under for a week, while she heals. Warren was… rather brutal," Giles said, lips thinning.

"So was I," Xander said, smiling coldly, and Giles flashed him a mirthless smile. "How's Jonathan and Spike?"

"Jonathan has woken up. He immediately asked how Willow was, and was most upset when he heard what happened. Spike… if he was human, he would be dead a hundred times over. He's still healing," Giles said. "No matter how much I dislike him for what he had done, he fought as hard as he could, and was very brave."

"Spike may be evil as they come, but he doesn't back down from a fight," Xander confirmed. "And he likes Willow for some reason."

"I like little Red because she doesn't treat me like scum," Spike replied, staggering painfully.

"Did you succeed in your Trials?" Xander asked. He already knew the answer, but asked anyway.

"Take a look," Spike replied, and Xander did.

"Well done," Xander said, touching Spike on the shoulder. Bruises disappeared, cuts healed, bones reformed and internal injuries were no more. In about five seconds.

"Bloody hell," Spike whispered.

"I'll be back in a bit," Xander said, nodding and disappearing in a blur. He had a job to do.

He flew towards the Cardiff rift again, and shot through, hunting down another world. The Doctor had taught him to explore, and never to turn aside when people were in need. And that was what he would do.

Meanwhile, in the Torchwood hub, Owen Harper frowned as the computer beeped.

"Jack, there's a massive spike in rift activity. Again. It's the same as the one a couple of days ago and the one a few weeks before that," Owen said. "It's like the same thing is going back and forth through the Rift over and over again."

Jack jogged down the stairs and examined the screen. Owen eyed him, looking for a spark of real emotion from behind the mysterious Captain's mask. He wasn't disappointed, as a flash of fear passed across Jack's face.

"Owen, leave this one alone. Just ignore it," Jack said, voice laced with urgency. "That goes for Tosh and Suzie as well, when I tell them."

"What is it Jack?" Owen asked.

"The most dangerous man alive," Jack said quietly. "Torchwood was set up to stop the Doctor. He makes the Doctor look harmless. He's called the Watchman, and if you ever meet him, run. Just run and hope he doesn't notice you or have reason to follow you."

"WHAT OF THE TIME LORDS?" the Dalek asked. "AND THE WATCHMAN?"

"Dead," the Doctor said quietly. "All dead. Even the Watchman burned at the end. Even he could die."

"Who is the Watchman?" Van Statten asked the Doctor. "You and the Dalek talked about him."

"An old friend of mine. A good man gifted with extraordinary power. That creature that's slaughtering its way through your soldiers? It fears him. He was the second most feared enemy of the Daleks. Because they could not stop him. Every Dalek that ran across him died. They called him the Golden Death. At the height of his power he destroyed billions of Daleks in a single engagement," the Doctor said. "He nearly turned the tide of the Time War."

"You said, second most feared," Van Statten said. "What did they fear the most?"

"Me," the Doctor said.

"Why you?" Van Statten asked.

"I'm the reason that that creature is unique," the Doctor said coldly. "They call me the Destroyer of Worlds and the Oncoming Storm."

"Created from the dregs of humanity," the Doctor whispered, looking at the Daleks in horror.

"That means they're part human," Rose said, clearly disgusted.

"You're lucky," the Doctor said, eyes narrowed as he glared at the Emperor. "Lucky you survived. Lucky that the Watchman died. Lucky, because we both know what he would have done if he saw you now!"

"The Watchman?" Jack asked with a frown. "He's the stuff of old legends, myths from Old Earth. Well, Dad told me he met him once, but I think he was joking."

"The Watchman was as real as you or I, Jack. One human chosen by chance to be imbued with vast power. He journeyed the Universe. We met, we travelled together. We fought in the Time War, side by side," the Doctor said. "He tore Skaro apart. He burned the Dalek fleet at Arcadia. He destroyed the Nightmare Child in the dying days of the Time War, taking three planets down in the process."

"HE SLAUGHTERED THE DALEKS!" the Emperor said, clearly angry. "HE BLASPHEMED AGAINST US!"

"DO NOT BLASPHEME!" the other Daleks chanted.

"He was worth more than a _billion_ Daleks," the Doctor snarled. "That man had power and he had the wisdom to use it well! So if anything, _you're _the blasphemers against a good man's memory!" He quieted down. "And that's all he is now. Memory, myth and legend. Like you should be."

"Anything apocalypse like?" Buffy asked. This was roughly translated as 'is there something large that Xander can kill before he goes stir crazy'. Xander had been sticking to them all like a burr, citing what had happened last time he'd left them.

"No, merely the odd demon, and more 'mysterious barbecue fork related incidents'," Giles replied.

Suddenly, Xander looked around the room. "Enough is enough," he said, and stood. "Spike, stay inside, in a darkened room with no windows, well away from any possible sunlight. Buffy, tell Angel to do the same."

"What are you doing Xander?" Giles asked.

Xander looked at him and said, "The Green Lantern corps, a comic book superhero group, sort of intergalactic policeman, had an oath: '_In Brightest Day, In Blackest Night, No evil shall escape my sight. All who worship evil's might, beware my power… Green Lantern's light!_'"

He looked around the room. "The world has languished under the boot of vampires for long enough. It's been in the Blackest Night for thousands of years. Now, I shall make it Brightest Day, and it will be _my_ light that evil fears. I have the power of a million exploding suns. It's time to use it."

Every jaw collectively dropped. "Xander," Giles said, "this is well intentioned, and I understand you completely…"

"But?" Xander said.

"But you will be completely destabilising the cosmic order! Who knows what will arise in place of vampires? And Xander, your words… they smack of hubris! You are talking as if you are a god!" Giles said, sounding a little panicked.

Xander looked at him, and said, "You're right. I'm not a god. I am _beyond _gods. I have _killed_ gods."

"There will be far reaching consequences," Giles warned.

"As far as I'm concerned, I _am _far reaching consequences," Xander replied. "Besides, with most vampires dead, and probably a few demons as well, with whatever's left too scared to come out of their caves… people won't have to live in fear. Buffy will be able to live a normal life. Don't you want that?"

"They won't fear vampires, certainly," Giles said, looking Xander dead in the eye. "But who says they won't fear you?"

Xander looked at him for a long moment, then said, "Warn Angel. It's happening tonight. And Giles… well, that is the cross I must bear." Then he disappeared with a whoosh of displaced air.

"Why does that last sentence not reassure me?" Giles whispered.

At midnight that night, Xander rose into the upper atmosphere, and closed his eyes, concentrating. Slowly, he began to glow, brighter and brighter until all that could be seen from below was an enormous ball of light.

Soon the Western hemisphere of the Earth was bathed in the light of a second sun. All over the lands touched by the light, vampires that didn't find cover quickly enough crumbled into dust. As the real sun began to rise, Xander stopped, suddenly feeling very tired. News outlets the next morning (if you could call it that) were full of news of 'The Brightest Day'.

At first it was dismissed as strange solar activity, then, as pictures of a white clad figure in upper atmo arose, taken by satellites, the people of earth began to accept that there was something else out there.

Something strong enough to create another day in the middle of the night. Not long after came the proclamations that it was the second coming of Christ. Then people began to look at why. Reports of vampires and creatures of the night were being taken more seriously, especially as they suffered a sharp drop off in the west after the event. At first, some people wondered if the figure did not like the east, for there had been no similar event, and the world nearly went to war over the suggestion that the east was not worthy, until the event repeated itself and the UN security council received a stark message.

Stencilled into the ground in front of the United Nations headquarters in Geneva was the message, 'I do not favour West or East. I could only do one at a time. I'm just a guy, trying to do my bit. And I AM NOT GOD. OR JESUS. Oh, and sorry about the property damage.'

Despite this denial and self-deprecation, Xander had set in motion great forces. Great forces that did not appreciate meddling mortals. The universe was out of balance and everything, even Xander, had an equal and opposite reaction.


End file.
